I just found Miller (fourth edition) and the "explanation" in there is,
in my opinion both uninformative and wrong. He does state Bernoulli's
principle, and it seems to be identical to Bernoulli's theorem, though
one wonders why another term is needed. In a footnote he states that
application of the principle is restricted to streamline flow, and he
states elsewhere "The whole [curve ball] phenomenon, called the *Magnus
effect*, depends on the viscous drag of the fluid as well as on
Bernoulli's principle." Thus he simultaneously disclaims and implicitly
invalidates his "explanation"!
Now I don't feel badly that I can't understand such an explanation, but
I would feel badly if I were to make that explanation to my students
and have them think that I did understand it. I might hoodwink 99% of
them (the ones some of you think are important) but the 1% who go on to
teach physics would eventually discover my deceit, or they would if I
didn't succeed in driving them away from physics altogether. Please tell
me who wins here.
I also looked at Hecht. He merely asks the question about the ball's
direction and draws a misleading streamline diagram (misleading because
the flow is not streamline flow). If I were to answer his question
naively I would come up with the wrong direction for the deflection.
As I said before, there are many real world phenomena I can explain to
my students in terms of simple physical principles without lying,
including many in fluid mechanics. I had the hydraulic ram explained to
me as a high school student. The Venturi effect can certainly be
introduced and demonstrated, and Bernoulli's theorem can be derived as
a marvelous counterintuitive example of the work-energy theorem in
simple classical mechanics. Let's leave curve balls and airfoils where
they belong, as advanced topics in aerodynamics.